Staying eco-friendly in today’s market is a smart idea. It used to be that your new product didn’t need to worry about recycling and the end of lifecycle disposal. The current trend with consumers is to seek out products that are environmental friendly, both on the manufacturing side and at the end when it’s time for disposal. Choosing a biodegradable resins option for your new product makes sense, but which option do you choose? We’ll explore the five top selections available that may be the best option for your new plastic injection molding project.
What is a Biodegradable Plastic?
Biodegradable plastics will degrade over time and turn back into base materials without any extra intervention from people or a supply of oxygen. Compared to petro-chemical plastics, the main difference between a biodegradable plastic and petrochemical plastic relates to carbon. Petroleum based plastics hold carbon after being formed. After they are disposed of, that carbon is slowly released back into the atmosphere through degradation or melting to be recycled. Biodegradable plastics do not release any carbon back into the environment after use. Carbon isn’t used in the initial manufacturing, and isn’t a byproduct as it degrades.
Biodegradable plastics are engineered plastics that is meant to degrade quicker than a basic petroleum based plastic. Biodegradable resins are typically decomposed by the action of living organisms like bacteria and fungi, which can eat the plastic and convert it back into a natural material. It is a perfect option for one-time use plastic that will be discarded after initial use. The most common types of biodegradable plastic resins used in plastic injection molding are:
- Thermoplastic Starch-based Plastics (TPS)
- Polyhydroxyalkanoates (PHA)
- Polylactic Acid (PLA)
- Polybutylene Succinate (PBS)
- Polycaprolactone (PCL)
Thermoplastic Starch-Based Plastics (TPS)
Starch-based thermoplastics (TPS) are inexpensive and easily available. They are often blended with other materials for use in plastic injection molding, but are commonly found in food packaging, takeout packaging for fast food, and one-time disposable utensils. Starch-based plastics are 100% biodegradable and can be carbon neutral. This may be a particularly good selling point for TPS as consumers have a basic understanding of carbon’s effect on global warming. They may choose TPS products because TPS can be carbon neutral when disposed of.
Polyhydroxyalkanoates (PHA) is a plastic resin produced by bacteria taking action on sugars or lipids. Various molecules are combined and the subsequent plastic resin has many different properties that benefit injection molding the environment. PHAs can withstand UV exposure without degradation, do not change when exposed to moisture, nor they do not absorb odors. These resisting qualities make them a perfect option for food packaging, cosmetic products, and some medical devices likes surgical mesh and sutures.
Polylactic Acids (PLA)
Polylactic acids (PLA) are made from tapioca, cassava, sugarcane, or cornstarch. PLAs are used in manufacturing a large number of consumer products, such as medical implant rods and screws. PLAs are also used widely in one-time use cups, disposable food packaging, and one-time use utensils.
Polybutylene Succinate (PBS)
Polybutylene succinate (PBS) is an aliphatic polyester with characteristics comparable to polypropylene. One major difference is that PBS will degrade naturally and result in water and CO2 being introduced into the environment. PBS is made from succinic acid, which is an organic chemical common to most living organisms. PBS is frequently used in food packaging, packaging for cosmetic products, medical implants, and dissolvable drug encapsulation. PBS is also often blended with Polyactic acids (PLAs) to modify characteristics concerning strength and impact resistance without changing affecting thermal or tensile properties.
Polycaprolactone (PCL) is commonly added in the production of polyurethanes to increase impact resistance and improve water, oil, solvents, and chemical resistance. It is derived from vegetable oils and frequently mixed with starch-based plastics (such as TPS) to decrease material cost or to adjust tensile characteristics of a particular material. PCLs are typically used in dissolvable drug delivery systems, dissolvable sutures after medical procedures, and other medical products to aid in tissue repair.
Can Hemp Upset the Biodegradable Plastic Market?
Hemp has become the new ‘it’ material that everyone has talked about in the last few years. It has a wide array of products that it can be used for and biodegradable plastic can be added to that list. Hemp based plastics can be infused with hemp fibers to increase strength and durability, and also blended with other plastics to change the base material characteristics. No machine changes are required to use hemp plastic in current injection molding machines, which makes it an ideal option to consider for a new product. Current uses of hemp plastics include products in the automotive and building industries, as well as food grade products directly sold to consumers.
The five main options mentioned, plus the addition of hemp plastics, give you many options to choose from for biodegradable resins as part of your next plastic injection molding product. If you don’t have a specific end of life scenario for your project, or don’t know which option is the best for your next invention, don’t feel overwhelmed. The experts at SEA-LECT Plastics are here to help. If you need advice on which biodegradable resin option would best for your product, or just need a sounding board to discuss the various options, we are ready to start your next project with you. Give us a call at (425) 339-0288 or email us at firstname.lastname@example.org. We have experts that can aid with resin selection on a new product to increase recyclability and reduce waste. We offer turn-key assembly options that reduce power requirements, and program management to see the complete development cycle through with success. At SEA-LECT Plastics, we specialize in military product applications, outdoor adventure gear, musical instruments, supporting the medical and consumer product industries. Our goal is to make your project efficient and cost-effective to manufacture, assemble, and ship no matter how complicated your concept is.
Matthias Poischbeg was born and raised in Hamburg, Germany. Matt moved to Everett, Wash., after finishing his bachelor’s degree in business in 1995 to work for Sea-Dog Corporation, a manufacturer, and distributor of marine and rigging hardware established in 1923.
In 1999, Matt took over the reins at Sea-Lect Plastics Corporation, a sister company of Sea-Dog and a manufacturer of plastic injection molded products with an in-house tool & die shop. Matthias Poischbeg is also a contributor to Grit Daily.